The present invention generally relates to eye surgery, and more particularly relates to a method and an apparatus, advantageously a small-diameter fragmatome, for removing retained lens fragments in a minimally traumatic fashion.
During cataract surgery, the natural lens may be removed from inside of the patient's eye. Conventional procedure for removal of the natural lens typically involves making a large (2.9 mm, or larger) incision into the eye and a second, smaller incision. Typically, two incisions are required to accommodate conventional instrumentation into the eye. One incision allows a tubular apparatus (a emulsification tip) into the eye to infuse saline solution to maintain pressure inside the eye and to emulsify and aspirate lens fragments. The second incision allows conventional instrumentation into the eye for various purposes, such as to assist in lens removal. The tubular apparatus emulsifies the lens, typically with ultrasonic or laser energy provided at the tip, causing the natural lens, once lifted toward the front of the eye, to break apart. Application of energy from the tip of the tubular apparatus causes the lens to break down into smaller pieces, small enough to be removed by suction.
It is important to remove all lens fragments before ending the operation. If lens fragments, and especially portions of the center of the lens, also known as the nucleus or the nuclear lens, shift into the back or posterior chamber of the eye, those lens fragments may cause severe trauma (including inflammation and blindness) if left unremoved. Occasionally lens fragments do get left behind, requiring a further procedure for subsequent removal. The conventional procedure is to remove the lens fragments using an additional procedure, by making further incisions into the eye, and removing the remaining lens fragments using a conventional fragmatome. In this additional procedure, three incisions are typically required to accommodate conventional instrumentation into the eye. One incision allows tubular apparatus into the eye to infuse saline solution to maintain vitreous pressure inside the eye. The second incision allows conventional instrumentation into the eye for various purposes, such as to provide light and/or suction. The third incision allows a conventional fragmatome into the eye. The fragmatome emulsifies the lens, typically with ultrasonic or laser energy provided at the tip, causing the lens to break down into smaller pieces, small enough to be removed by suction. Relatively large incisions are suffered by the patient, requiring suturing. Thus, the patient's trauma and healing time is increased.
A drawback to conventional removal of lens fragments from the back of the eye, as described above, is that conventional fragmatomes are comparatively large in design. The tips are typically 20-gauge (about 0.81 mm) in diameter or larger, requiring the incision through which they enter the eye to be correspondingly large. Popular conventional fragmatomes also combine, into one instrument, a tip to provide emulsification energy and a tip to aspirate fragments. This combination causes an even greater potential for a need to introduce a large profile instrument into the eye.
Such large incisions in the eye, as described above to accommodate conventional instrumentation, typically require suturing after the procedure is complete. This suturing, and the healing of the sutured wounds, adds to the trauma suffered by the patient in the operation. Post-operative healing time is also increased.
Current thinking to address some of the above-described drawbacks of conventional surgery to remove lens fragments from the back of the eye appears to focus on miniaturizing the popular combination fragmatome-aspirator, which by its nature has a larger operational profile than either an individual fragmatome or suction tube. Current thinking further appears to be stuck on the notion that emulsification and fragmentation of the removed lens tissue must be done at the same time as removal from the eye of the lens fragments.
Recent professional commentary in the art has recognized a long felt but unsolved need for apparatus and methods for removing lens fragments using a small gauge fragmatome, advantageously 23-gauge (about 0.57 mm) or smaller in operative diameter. In his article “Combined 20-gauge and 23-gauge pars plana vitrectomy for the management of posteriorly dislocated lens: a case series” (published in the 18 Jun., 2010 edition of the professional magazine “Clinical Ophthalmology”), P. Kongsap teaches that small gauge instrumentation (typically 23-gauge or smaller) may enter the eye cavity though incisions small enough not to require suturing, minimizing trauma to the patient and reducing recovery time. However, when lens fragments are left in the posterior eye cavity, removal of those fragments through those same small incisions is made difficult by the unavailability of a small gauge (23-gauge or less) fragmatome.
As can be seen, there is a need for a method and an apparatus for removing lens fragments from the eye in a minimally traumatic fashion, and in particular using a small gauge fragmatome entering the eye through smaller incisions that will not require suturing. An improved method using such a small gauge fragmatome could also reduce patient trauma and post-operative healing time.